Such a brace is disclosed in European patent application 670 152 A1. In the known knee brace, an inflatable padding is used to correct the longitudinal axis of the leg, said padding being disposed directly at the side next to the knee and expanding through inflation such as to exert a pressure directly on the knee. Taking into consideration the position of the knee-distal straps placed around the upper leg and lower leg, the hinged rail, which extends laterally over the knee, exerts a moment on the knee, which, depending on the position of the hinged rail on the inside or outside of the leg, is thus brought towards a knock-knee position or bow-legged position. This results in two effects: firstly, a pressure is exerted directly at the side on the knee and therefore on the pain-sensitive joint capsule; secondly, when the knee is bent, the inflatable padding must slide on the skin surrounding the knee, this, of course, being associated with friction and leading, if the brace is worn for lengthy periods of time and especially during sporting activity, to grazing of the corresponding points on the skin.
A further design of knee brace for correcting the longitudinal axis of the leg is disclosed in U.S. Pat. No. 5,302,169. In this. brace, the two arms of a hinged rail extending over upper leg and lower leg are brought by means of adjusting screws into a desired oblique position with respect to a hinged connection consisting in relatively complex manner of two interconnected ball-joint-like sliding bearings.
With this knee brace, it is inevitable that there will be compressive forces acting on the knee, this having a considerably adverse effect on the wearing of such a brace, particularly when the knee is moved. Furthermore, the screw-type adjustment of the two arms of the hinged rail, accomplished via relatively short lever arms, allows a considerable elastic hysteresis of said arms, with the result that the known knee brace cannot be guaranteed to provide a reliable therapeutically required correction of the leg position.
A further knee brace is disclosed in U.S. Pat. No. 4,796,610, in which attached to the end of the arms of a hinged rail are pads which are in contact with the upper and lower leg. Said knee brace is intended to absorb forces occurring transversely with respect to the leg in the region of the knee joint and thereby to prevent injuries of the kind that repeatedly occur especially during the playing of sports. The knee brace serves, therefore, in particular to prevent sports injuries; it is not designed to bring about a conscious correction of the longitudinal axis of the leg.
In addition, it is known, for example, from EP 0 684 026 A1 to provide inflatable pads at the hinged rails of a knee brace for the purpose of padding the hinged rails against the leg, said inflatable pads being able to be individually inflated by the wearer such that the wearing of the knee brace is as convenient as possible, i.e. the pads serve to adapt the hinged rails individually to the form of the respective leg, particularly also to the change thereof during the wearing of the knee brace over the course of a day, in order in this manner to achieve a particularly good fit between the knee brace and the leg.